Author(s): Devojit Das, RICHARD J CUTHBERT, RAM D JAKATI, VIBHU PRAKASH
Veterinary use of the non-steroidal anti-inflammatory drug (NSAID) diclofenac has been shown to be the major cause of the collapse of populations of three Gyps vulture species endemic to South Asia. The White-rumped Vulture Gyps bengalensis, Indian Vulture G. indicus and Slender-billed Vulture G. tenuirostris, have declined by more than 98% in the Indian subcontinent since the early 1990s, and are now all listed as 'Critically Endangered' (IUCN 2004). Gyps vultures are exposed to diclofenac through consuming the contaminated carcasses of livestock that have been treated with the drug shortly before death and die from kidney failure, with clinical signs of extensive visceral gout and renal damage. These clinical signs and diclofenac residues have been found in carcasses of wild G. bengalensis and G. indicus, and in G. bengalensis either dosed with diclofenac orally or given tissues from diclofenac treated livestock. Research on White-backed Vultures G. africanus, Eurasian Griffons G. fulvus and Cape Vultures G. coprotheres has established that these three species are about as sensitive to diclofenac as G. bengalensis, with birds dying with the same clinical signs of visceral gout and characteristic renal damage. This experimental testing has established that diclofenac is toxic to four species of vultures in the genus Gyps, but information on the toxicity of diclofenac to other members of the genus is lacking.